1. Field of the Invention
This invention relates to the field of hangers suitable for suspending signs, temporary wiring, sheets or tarpaulins, such as heavy gauge polyethylene sheets used in asbestos removal operations.
2. Related Art
Various circumstances require the hanging of objects from numerous, closely set, and desirably strong hangers. One example is the temporary hanging of decorative Christmas or other holiday lights; the supports must be placed close together and be strong enough to support the wiring. Another example would be the hanging of banners and signs, which are desirably supported across their top edge in order to reduce or avoid sagging in the middle. Yet another example is from the field of asbestos removal wherein plastic sheeting must be held in place to provide a barrier against dispersal of asbestos fibers. The process of removing carcinogenic asbestos from structures requires that the area in which the work is being done be isolated from the environment. This isolation is accomplished by sealing the area with multiple layers of heavy gauge polyethylene sheets. These sheets may be quite heavy, e.g., 6 mils in thickness. The sheets must be hung around the entire perimeter of the room or area to be isolated, laid to cover the floor, and then sealed closed, for example, with duct tape, to prevent asbestos fibers from leaking out from between the seams. The area is then maintained at a slight negative atmospheric pressure in order to ensure that any leaks in the enclosure are of clean outside air into the room, and not of asbestos fibers from the room. As is well known in the art, the slight negative pressure is maintained using an air filtration unit to suck air from the room, filter or scrub it, and then release it into the environment. The system works most efficiently when the leaks in the isolation system are kept to zero. Thus, there should be no holes in the plastic. Similar circumstances prevail whenever a vapor or particulate barrier must be erected.
Hanging large sheets is a difficult process. In known methods of hanging, the sheets are hung either using strips of furring nailed to the wall, or are adhered directly to the wall with tape or adhesive, or are hung from hooks. All of these methods present problems, chiefly in the form of damage to the wall. Other problems include the expenditure of time and labor in the hanging process, and the difficulty of maintaining a tight seal.
One reference to these problems can be found in U.S. Pat. No. 5,207,403, issued May 4, 1993 to D. T. Penniman and entitled xe2x80x9cDevice and Method to Support Polyethylene or Other Sheetingxe2x80x9d. Penniman teaches the use of a flat, triangular-pointed prong stamped out of a thin sheet metal bracket-like device. The device has a clip, as illustrated in FIG. 2 of the ""403 Patent. The clip enables the device to be suspended from ceiling tile support rails. When Penniman""s device is adhered to a wall, however, nails, screws, glue or tape are needed and these methods of support cause damage to the wall, and also require significant labor and materials. While the device of the ""403 Patent is designed to allow users to impale the plastic onto the hook and let it dangle therefrom, the heavy gauge plastic required in asbestos removal operations causes the thin prong to bend or pull out of the wall. The weakness of the thin sheet metal also makes the hook prone to bend if tension is transmitted to it by the suspended plastic, for example, by a user accidentally stepping onto or otherwise tugging a projecting fold of the plastic. The clip portion engages only the exposed horizontal bottom of the ceiling tile support rail, and is thus easily pulled free by accidental tugs on sheets suspended from it.
In order to avoid damage to the prong and avoid pulling the device from the support rail or wall, it is necessary to add a separate step of pre-slitting the plastic with a knife in order to create a hole for the prong to pass through and thereby reduce mechanical stress on the prong. The slit made by the knife must necessarily be wide enough to span the width of the wide hook stamped out of the thin sheet metal. This slit allows ingress of air when the blower is working or, should the blower malfunction or be turned off, allows the egress of asbestos fibers from the room.
It would be advantageous to have easily manufactured hangers, capable of supporting objects such as, for example, plastic sheeting, tarpaulins, signs, banners, or temporary wiring or lighting, made of a material which allows easy penetration of plastic sheeting and which are strong enough to support such objects and resist mechanical deformation. It would also be advantageous for such hangers to cause minimal damage to the walls of a structure on which, e.g., plastic sheeting is suspended, and to make holes in the plastic sheets which are substantially entirely filled and closed by the hanger""s penetration of the plastic sheeting.
In accordance with the present invention there is provided a wire hanger for supporting material therefrom. The wire hanger comprises a length of wire configured to define a shank having a suspension hook formed at one end thereof and a retainer formed at the opposite end thereof, the retainer being dimensioned and configured to be mounted to a support structure.
In one aspect of the invention, the suspension hook has a sharpened tip, for example, the tip may have a wedge-like surface.
Another aspect of the present invention provides that the retainer is dimensioned and configured to engage a support structure selected from the group consisting of a ceiling tile support rail, a pipe, a door top, and a wall, for example, the retainer may be dimensioned and configured to engage such support structure having a T- or L-shaped cross section.
In a particular aspect of the present invention, the retainer is dimensioned and configured to engage such support structure having a T-shaped cross section, comprised of a vertical leg and a horizontal leg. In this aspect, the wire hanger comprises an off-set extension extending from the shank, a longitudinal extension extending from the off-set extension, and a retainer hook formed at the end of the longitudinal extension, the retainer hook being dimensioned and configured to fit over such vertical leg.
Other aspects of the present invention provide the following features, alone or in combinations of two or more thereof: the wire hanger may have an eye through which an attaching member, e.g., a nail or screw, may be placed to secure the wire hanger to a wall; the retainer may comprise a straight piece of wire dimensioned and configured to be driven into such support structure, the straight piece of wire extending from the shank at an angle of about 70 to 110xc2x0; the retainer may lie in a first plane and the hook may lie in a second plane different from the first plane; the angle between the first plane and the second plane may be from about 30 to 60 degrees; the retainer may have a retainer hook formed thereon and the retainer hook and the suspension hook may extend in opposite directions from the shank; the retainer hook and the suspension hook may have different radii; the retainer may have a retainer hook formed thereon and the retainer hook and the suspension hook may extend in the same direction from the shank; the retainer hook and the suspension hook may have different radii; and wire may comprise an annealed spring wire.